Comparative Metallurgical and Mechanical of Nd:YAG laser welding of Austenitic stainless steels

Laser welding is a significant method for welding all kinds of alloys. High speed welding, low distortion and easy automation are the advantages of this method. In this study, pulsed Nd:YAG laser butt joint welding was performed on 304 and 316 Austenitic stainless Steels workpieces. All the parameters were designed by Full Factorial Method which the center point was repeated for 10 times. Henceforth, the effect of power, pulse duration, laser velocity and chemical composition on width and depth of welding area, ultimate tensile strength, elongation and Ferrite Number were studied. The welding process was performed in 1.2 and 1.8 KW as power, 3 and 4.4 ms as pulse duration and 0.2 and 0.8 mm/s as velocity of welding. Thus, the upper level of input parameters were selected as the optimal case. This was done by surveying all the samples to achieve maximum UTS, size of the weld and Ferrite Number. In these conditions, output error for width of weld, depth of weld, U.T.S, elongation and Ferrite Number was 2, 5, 1.6, 25 and 2%.